Stacking and transferring unit

ABSTRACT

Generally rectangular objects are delivered to an elevator platform and lifted past a series of supporting plates which pivot to let them pass, butt swing down to prevent them from lowering with the elevator platform. When a stack is complete, it is transferred laterally into a hopper. Retractable means are provided to engage and support the trailing edges of the objects during the transfer operation.

United States Patent [191 Tull, III

[ Mar. 11, 1975 1 STACKING AND TRANSFERRING UNIT [75] Inventor: HerbertG. Tull, III, Charlottesvill [7 3] Assignee: Hoerner WaldorfCorporation, St.

Paul, Minn.

[22] Filed: Dec. 30, 1971 [211 Appl. No.: 213,886

Related U.S. Application Data [63] Continuation-impart of Ser. No.73,967, Sept. 21,

1970, Pat. No. 3,701,314.

521 U.S. c1 214/6 BA, 271/212 [51] Int. Cl. B65g 57/30 [58] Field ofSearch 214/6 BA, 6 H, 6 DK, 6 B; 271/212 [56] References Cited UNITEDSTATES PATENTS 3,013,369 12/1961 Wilson et a1. 214/6 BA 3,124,059 3/1964Labombarde 214/6 DK Groll 214/6 DK 3,451,562 6/1969 Sjostrom 214/6 BA3,486,636 12/1969 Stroup 214/6 BA 3,519,144 7/1970 Calistrat 214/6 BA3,545,367 12/1970 Smith et al.. 214/6 BA 3,622,017 11/1971 Mueller 214/6BA 3,659,728 5/1972 Reinecke 214/6 H Primary Examiner-Robert G. SheridanAssistant Examiner-Leslie .1. Paperner Attorney, Agent, or Firm-RobertM. Dunning; Jerry F. Best [57] ABSTRACT Generally rectangular objectsare delivered to an elevator platform and lifted past a series ofsupporting plates which pivot to let them pass, butt swing down toprevent them from lowering with the elevator platform. When a stack iscomplete, it is transferred laterally into a hopper. Retractable meansare provided to engage and support the trailing edges of the objectsduring the transfer operation.

2 Claims, 8 Drawing Figures PATENTED'MRI H915 3', 870, 1 66 sum 1 of 3INVENTOR HERBERT G. 721M. 122' BY iZ lm mQng ATTORNEY PATENTEDHARI 1I975 sum 2 o 3 INVENTOR HERBERT G. TULL ZZZ' BY 831mg ATTORNEY PATENTED1 I975 3, 870.156

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i4 INVENTOR HERBERT 6. 7211.1. 112' u ja j w g ATTORNEY STACKING ANDTRANSFERRING UNIT BACKGROUND OF THE INVENTION Various means have beenprovided for stacking items one above another. Devices such as containersealers apply adhesive to the closure flaps of the containers and thenstack the closed containers one above the other to hold the flaps closeduntil the adhesive has set. Means are usually provided for pushing theuppermost container off the stack and onto a suitable slide or conveyor.

For example, in Pat. No. 2,997,830 issued Aug. 29, 1961, to Iver L.Nelson, corrugated folders are closed, and are stacked one aboveanother. Lugs are provided for engaging beneath opposite sides of thelowermost folder for holding the folders from dropping in the stack.However, I do not know of any previous structure embodying the stackingfeatures of the present invention.

SUMMARY OF THE INVENTION The present structure comprises a stackingapparatus capable of stacking and transferring material such as hands ofbags or similar products which are relatively flexible. The presentdevice receives hands of bags,

each hand including, for example, 25 bags in superimposed relation. Dueto the fact the closed ends of the bags are substantially thicker ,thanthe open ends thereof, the groups or hands of bags are alternated sothat the closed ends of alternate hands overlie the open ends of bags ofthe intermediate hands. This is accomplished by a collator which acts tocollect a predetermined number of bags and turn them in one direction oranother for delivery to the stacker. Obviously, such an apparatus is notnecessary if the objects being stacked are of equal thickness throughouttheir area.

A feature of the present invention resides in the provision of pivotallymounted supporting plates designed to engage all four edges of thelowermost rectangular bag of each hand. This is desirable in view of thefact that the flexibility of the bags may otherwise cause them to sagsufficiently to pass between the supports if supported only on twoopposite sides. These plates are normally horizontal, but swing upwardlyas each hand of bags is raised by a suitable elevator means. When theelevator means is lowered, the edges of the bags rest upon thesupporting plates and the bags are supported thereby on all four edges.

A further feature of the present invention resides in the provision of ameans for supporting the rear edges of the stack of bags as the bags aretransferred from stacking position to a suitable receiving hopper. Theelevator which lifts the bags is raised to the level of the floor of thehopper and the stack is moved laterally into the hopper. It is desirableto lower the elevator during the time the bags are moving laterally intothe hopper in order to speed up the operation of the apparatus and topermit the lowering of the elevator to receive another hand of bags. Inorder to support the trailing edge of the bags as they are moved, hookmeans are provided on the lower edge of the bag moving or transferringapparatus which engage beneath the trailing edge of the lowermost bag ofthe stack to hold the bags from dropping. Means are provided fornormally retracting these hooks during the stacking operation, andautomatically projecting the hooks beneath the bag stack as the transfermovement of the stack starts.

These and other object and novel features of the present invention willbe more clearly and fully set forth in the following Specification andClaims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational viewshowing the end portion of the collator, the stacker, and hopper,showing the general arrangement of parts.

FIG. 2 is a perspective view of the end of the collator and intake endof the stacker.

FIG. 3 is a horizontal sectional view through the stacker, the positionof the section being indicated by the line 3-3 of FIG. 2.

FIG. 4 is a sectional view through the lower portion of the stacker, theposition of the section being indicated by the line 44 of FIG. 3.

FIG. 5 is a view similar to FIG. 1 showing the stack being transferredto the hopper.

FIG. 6 is an enlarged vertical sectional view showing the stack beingtransferred into the hopper, and the elevator in lowered position.

FIG. 7 is a diagrammatic perspective view of the lower portion of thetransfer mechanism in stack transferring position.

FIG. 8 is an enlarged sectional detail showing one of the hooks forsupporting the trailing edge of the stack during the transfer thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION The transferand stacking unit is indicated in general by the letter A. The unit Aincludes a frame which is indicated in general by the numeral 10 andincludes supporting legs 11 and 12 which form a part of the frame.Generally horizontal frame members 13 at the top of the legs 11 supportsa conveyor chute 14 through which the hands of bags are pushed, thecollator and the means for transferring the hands not being illustratedin the drawings. The hands of bags are illustrated in general by thenumber 15. Due to the fact that the bags are thicker at one end than atthe other, the hands are alternated,'with the closed ends of the bags ofalternate hands overlying the open ends of the bags of the intermediatehands.

An elevator platform which is indicated in general by the numeral 16 isdiagrammatically shown in FIGS. 1, 4, 5 and 6 of the drawings. As shownin FIGS. 1 and 5, the elevator platform 16 is supported by a pair ofgenerally L shaped legs 17 having horizontal arm portions 19 at theirlower ends attached to vertical tubular slides 20. The slides 20 areslideably supported by slide rods 21 extending between a lug 22 on theframe leg 11. and the horizontal frame member 13 as indicated at 23. Anarm 24 is pivotally connected at 25 to the upper end of a link 26, thelower end of which is connected at 27 to a lug 29 on a plate 30connecting the ends 19 of the legs 17. Oscillation of the arm 24 about apivot axis acts to raise and lower the supporting legs 17 and to raiseand lower the elevator platform 16. The means for oscillating an armsuch as 24 is well known, and not illustrated.

As indicated in FIG. 1, in the lowered position of the platforms 16, theplatform is substantially coplanar with the bottom of the chute 14. Asis indicated in FIG.

5 of the drawings, in the elevated position of the elevator 16, the topof the elevator is substantially coplanar with the lower plate 31 of ahopper 32. The hopper 32 is designed to accommodate the stack of bags.In actual practice, the hopper is pivotally supported in a mannerillustrated in my previous application for patent which is referred toabove. As the present application refers only to the stacking andtransferring apparatus. the means of supporting the hopper is notdisclosed in detail in the present application. The hopper supportingarm is indicated in FIGS. 4 and 6 of the drawings by the numeral 33.

The hopper 32 includes partial side plates such as 34 between which thestack is forced. As indicated in 2 and 3 of the drawings, a side plate35 is also provided on the frame between which the bags are stacked. Thetrailing edges of the bags are also held in position during the stackingoperation by a pair of transfer bars 36 which are held in spacedrelation by a transverse bracket 37 and other means to be described. Thebracket 37 is connected at each end to slides 39, each ofwhich isslideable in a horizontal generally U-shaped frame 40. The bracket 37 ismoved horizontally by a piston rod 41 connected to a piston in thecylinder 42 mounted on the frame 10.

As indicated in FIGS. 2 and 3 of the drawings, the platform 16 includesa central plate 43 and a pair of side plates 44 connected in spacedparallel relation by connecting members 45. The reason for thisarrangement is to provide slots in the upper surface of the platform fora purpose which will be later described. The collator chute 14 isprovided with a pair of laterally extending wings 46 which act tosupport a pair of vertical angle brackets 47. A cross bar 49 ispivotally connected as indicated at 50 to the upper ends of the anglebrackets 47. A pair of vertical mounting bars 51 extend downwardly fromthe cross bar 49, the upper ends of which are engageable with thetransfer bars 36. Pivot blocks 52 are provided on the lower ends ofthemounting bars 51. Stacking guides 53 extend downwardly from the blocks52 and curve outwardly at their lower ends in order to assist in guidingthe hands of the bags as they are elevated.

A bag support plate 54 is pivotally supported between the pivot blocks52. The bag supporting plate 54 is held from movement in a clock-wisedirection from the position indicated in FIG. 4 of the drawings by asuitable stop 55 or other such means. The bag supporting plate 54 isfree to pivot in a counter clockwise direction toward vertical positionso as to permit the bags to move upwardly.

A frame member 56 is supported beneath the lower plate 31 of the hopper.An L-shaped block 57 is mounted on each side of center of the hopper,the position of these blocks being indicated in FIG. 3 of the drawings.A bag supporting plate 59 is pivotally supported as indicated at 60between the blocks 57, the plate 59 normally resting upon a cross bar 61connecting the blocks 57. The bag supporting plate 59 is pivotal in aclockwise direction from the position shown in FIGS. 4 and 6 so as topermit bags to swing the bag supporting plates upwardly, but to hold thebags from moving downwardly with the elevator platform 16.

As indicated in FIG. 3 of the drawings, brackets 63 are fixedlysupported in spaced opposed relation upon frame members 64 arranged onopposite sides of the elevator platform 16. These brackets 63 pivotallysupport bag supporting plates 65 as indicated at 66. The plates 65normally rest upon the frame member 64 and are held in horizontalposition thereby. However the plates 65 are free to pivot upwardly inthe manner of the other bag supporting plates 54 and 59.

The elevator platform 16 is of somewhat smaller dimensions than thebags, the outline size of the bags being indicated by the broken line 67in FIG. 3. Ac cordingly, the hands of bags may be elevated by theplatform 16, the bags pivoting the various bag supports upwardly topermit passage thereof. The platform 16 is reciprocated upwardly untilit is substantially coplanar with the lower plate 31 of the hopper 32.As the platform 16 is lowered, the hands of bags are engaged by thevarious bag supporting plates so as to hold the bag in an elevatedposition. The platform 16 may then move downwardly to the dotted outlineposition in FIG. 4 of the drawings and as shown in full lines in FIG. 6thereof. In this position they are adapted to receive another hand ofbags. It is important to note in FIG. 4 of the drawings that the handsof bags 15 which are supported by the pivotal plates tend to sagdownwardly at the center although the sag is insufficient to disengagethe bags from the pivotal supporting plates. This sagging of thelowermost hands of the bags is of assistance to the operation of theapparatus as the bags rest upon the top of the hand being elevated andtend to hold the hands in vertical alignment. The tendency for the handsto shift in any direction is prevented by the engagement with the handbeing lifted as is indicated in FIG. 4.

When a sufficient number of hands has been accumulated, transfer meansis actuated to transfer the stack of bags into the hopper 32. When thestack is complete, fluid is directed to the cylinder 42 which moves thetransfer bars 36 to the right as indicated in the drawings, forcing thehands of bags 15 into the hopper 32. The transfer operation is initiatedwhile the elevator platform 16 is in an elevated position. Means areprovided to support the trailing edges of the bags as they aretransferred, and once the forward or leading edges of the bags areengaged by the bottom plate 31 of the hopper, the elevator platform 16may move downwardly to receive another hand of bags.

With reference now to FIG. 8 of the drawings, the lower ends of thetransfer bars 36 are provided with generally L-shaped notches 70. Hookelements 71 are pivotally supported as indicated at 72 to the transferbars, the hook elements being urged in a counter clockwise direction bya suitable spring 73. The lower ends of the hook elements 71 areprovided with hook projections 74 designed to extend beneath thelowermost bag of the lowermost hand. The rear surface 75 of each hookelement 71 is normally flush with the rear edge 76 of the transfer bar36.

As is indicated in FIG. 4 of the drawings, when the transfer bars 36 arein normal or in retracted position, the upper corner 77 of each hookelement 71 has engaged the surface of a corresponding vertical mountingbar 51, and the hook element 71 has been swung into vertical position inthe notch as is indicated in this Figure. However, as soon as thetransfer bars 36 start into motion, the springs 73 expand and pivot thelower end of the hook elements beneath the trailing edges of the bags15, as indicated in FIGS. 6 and 8 of the drawings. FIG. 7 indicates inperspective the position of the hook elements when the transfer bars arein movement.

The operation of the apparatus is believed evident from the foregoingexplanation. The hands of bags are delivered from the collator chute l4unto the elevator platform 16. The hands of bags are then elevated pastthe bag supporting plates, swinging these plates upwardly in order topass by them. The elevator platform 16 then descends into position topick up another hand of bags. The bags are supported by the bagsupporting plates during the downward movement of the platform 16.

When the stack is completed, the transfer bars 36 are moved to the rightto slide the stack of bags unto the hopper bottom plate 31. As thetransfer bars start to move, the hook elements 71 swing beneath thetrailing edges of the bags to support the bags during the remainder ofthe operation. The hook elements 71 are aligned with the space betweenthe platform plates 43 and 44 so that the hooks may move while theplatform is still in elevated position or until the bags are forcedsufficiently unto the operable bottom plate 31 to insure there movementinto the hopper.

In accordance with the Patent Statutes, l have described the principlesof construction and operation of my improvement in STACKING ANDTRANSFER- RlNG APPARATUS; while I have endeavored to set forth the bestembodiment thereof, I desire to have it understood that obvious changesmay be made within the scope of the following Claims without departingfrom the spirit of my invention.

I claim: 1. A stacking apparatus for use in combination with generallyflexible rectangular objects including:

an elevator platform, two pairs of supporting plates, the plates of eachpair being in spaced parallel relation with the plates of one pair insubstantially right angular relation to the plates of the other pair,said plates engaging all four edges of said objects,

means pivotally supporting each of said plates adjacent the outer edgesthereof for movement from a generally horizontal position to an upwardlyand inwardly inclined position, said platform being of proper dimensionsto pass between said plates in horizontal position thereof,

guide means guiding the objects against said plates upon upward movementof said platform, pivoting said plates upwardly as they pass the plates,said plates swinging downward to horizontal position after the objectspass therebetween, whereby the flexible objects will sag downwardly nearthe central portions thereof,

means for reciprocating said platform,

transfer means engageable with a series of objects stacked upon saidsupporting plates to move said objects out of alignment with saidelevator platform,

said transfer means including laterally spaced bars,

5 and including,

hook-shaped elements pivotally secured to the lower ends of said bars,

said elements, in one position, engaging beneath the trailing edges ofsaid stacked objects during move- 10 ment thereof by said transfermeans, and are retracted in a second position, means urging saidhook-shaped elements toward said one position, and means holding saidhook-shaped elements in said second position prior to movement of saidtransfer means.

2. A stacking apparatus for use in combination with generally flexiblerectangular objects including a pair of supporting plates, said platesbeing in spaced parallel relation engaging opposite edges of saidobjects,

means pivotally supporting each of said plates adjacent the outer edgesthereof for movement from a generally horizontal position to an upwardlyand inwardly inclined position,

an elevator platform supported for vertical reciprocation,

said platform being of proper dimensions to pass between said plates inhorizontal position thereof,

upward movement of said platform raising said objects against saidplates, pivoting said plates upwardly as they pass the plates, saidplates swinging downwardly to horizontal position after the objects passtherebetween,

transfer means engageable with a series of objects stacked upon saidsupporting plates to move said objects out of alignment with saidelevator platform,

said transfer means including laterally spaced bars.

and including,

hook-shaped elements pivotally secured to the lower ends of said bars,

said elements, in one position, engaging beneath the trailing edges ofsaid stacked objects during movement thereof by said transfer means, andare retracted in a second position,

means urging said hook-shaped elements toward said one position, and

means holding said hook-shaped elements in said second position prior tomovement of said transfer means.

1. A stacking apparatus for use in combination with generally flexiblerectangular objects including: an elevator platform, two pairs ofsupporting plates, the plates of each pair being in spaced parallelrelation with the plates of one pair in substantially right angularrelation to the plates of the other pair, said plates engaging all fouredges of said objects, means pivotally supporting each of said platesadjacent the outer edges thereof for movement from a generallyhorizontal position to an upwardly and inwardly inclined position, saidplatform being of proper dimensions to pass between said plates inhorizontal position thereof, guide means guiding the objects againstsaid plates upon upward movement of said platform, pivoting said platesupwardly as they pass the plates, said plates swinging downward tohorizontal position after the objects pass therebetween, whereby theflexible objects will sag downwardly near the central portions thereof,means for reciprocating said platform, transfer means engageable with aseries of objects stacked upon said supporting plates to move saidobjects out of alignment with said elevator platform, said transfermeans including laterally spaced bars, and including, hook-shapedelements pivotally secured to the lower ends of said bars, saidelements, in one position, engaging beneath the trailing edges of saidstacked objects during movement thereof by said transfer means, and areretracted in a second position, means urging said hook-shaped elementstoward said one position, and means holding said hook-shaped elements insaid second position prior to movement of said transfer means.
 1. Astacking apparatus for use in combination with generally flexiblerectangular objects including: an elevator platform, two pairs ofsupporting plates, the plates of each pair being in spaced parallelrelation with the plates of one pair in substantially right angularrelation to the plates of the other pair, said plates engaging all fouredges of said objects, means pivotally supporting each of said platesadjacent the outer edges thereof for movement from a generallyhorizontal position to an upwardly and inwardly inclined position, saidplatform being of proper dimensions to pass between said plates inhorizontal position thereof, guide means guiding the objects againstsaid plates upon upward movement of said platform, pivoting said platesupwardly as they pass the plates, said plates swinging downward tohorizontal position after the objects pass therebetween, whereby theflexible objects will sag downwardly near the central portions thereof,means for reciprocating said platform, transfer means engageable with aseries of objects stacked upon said supporting plates to move saidobjects out of alignment with said elevator platform, said transfermeans including laterally spaced bars, and including, hook-shapedelements pivotally secured to the lower ends of said bars, saidelements, in one position, engaging beneath the trailing edges of saidstacked objects during movement thereof by said transfer means, and areretracted in a second position, means urging said hook-shaped elementstoward said one position, and means holding said hook-shaped elements insaid second position prior to movement of said transfer means.